Recently, economical and popular networking technologies based on compact devices of various kinds are emerging or being commercialized. With various home appliances such as refrigerators, TVs, washing machines, PCs, and audio equipments connected to a home network, people can use the appliances comfortably. To implement home networking as above, UPnP™ (hereinafter, it is called as UPnP for short) specification has been proposed.
A basic UPnP network consists of a plurality of UPnP devices, service, and a control point (CP). Service in the context of UPnP network corresponds to a smallest control unit on a network, being modeled by a state parameter. CP (Control Point) in an UPnP network corresponds to a control application equipped with a function for detecting and controlling other devices and/or services, being operated in an easy to handle physical device such as a PDA. CP can also be realized in a device by further incorporating a renderer service which displays an image by rendering media data. Therefore, a plurality of CPs can exist on an UPnP network; a user can choose and utilize a handy CP depending on the user's current location or employed device, thereby controlling operations on a desired service.
If a home network as described above is implemented at a particular place, e.g., in home, a user can make good use of desired operations such as duplicating or transferring data among dissimilar devices irrespective of the user's location. In addition, a plurality of users can share the same devices at the same place simultaneously.
When a plurality of users use devices connected to a network simultaneously or sequentially or make a plurality of tasks carried out simultaneously or sequentially on the devices connected to a network, required data transfer rates may exceed the bandwidth provided by the network. In this case, network access for data transfer must be limited.
For example, with a multitude of contents data being streamed through a network, if additional network access is requested and current network cannot meet bandwidth requirement demanded by the request, the request is refused or if the priority of additional access request is higher than that of a part of a current streaming connection, the current streaming connection is released. In this case, a user watching streaming contents experiences abrupt disconnection of the contents.